Use of Response Surface Metamodels for Damage Identification of a Simple Nonlinear System

Metamodels have been used with success in many areas of engineering for decades but only recently has their use in the field of structural dynamics started to be explored. This research applies the approach of metamodeling to the damage identification problem in structural dynamics. In this case, a metamodel is a reduced order model, constructed by empirically fitting a model to a set of points in the design space. Points in the design space may be chosen using a design of experiments approach. Then a polynomial model is fit to the points using a multiple regression fitting scheme. This empirical fit allows models to be constructed that relate damage parameters of interest (such as stiffness reduction and its location) to measurable output features (e.g. natural frequencies). The method has been demonstrated and its success quantified for simple linear and nonlinear simulations.